Reversible fluid flow machine



Sept. 29, 1964 LAlNG 3,150,815

REVERSIBLE FLUID FLOW MACHINE Filed Sept. 5, 1962 4? 40 36161 54 INVENTOR Nikolaus Lcing jM M,

- wdaz /uxm ATTORNEYS United States Patent 3,150,815 REVEESEELE FLUID FLUW MAQHINE Nikolaus Laing, Rosenhergstrasse 24A, Stuttgart, Germany Filed Sept. 5, 1962, Ser. No. 221,614 Claims. ((31. 23ii--d2) This invention relates to a flow machine for inducing movement of fluid which term is to be understood as comprehending both liquids and gases and this application is a continuation-in-part of application Serial No. 671,114, filed July 7, 1957. The invention relates more particularly to a flow machine of the cross-flow type comprising a hollow drum-shaped bladed rotor mounted for rotation about the axis of the drum and having means cooperating with the rotor to guide the whole fluid throughput of the machine through the rotor and at least twice through the path of the rotating blades in a direction transverse to the rotor axis.

An object of the invention is to provide a flow machine of the type described which is readily controllable in output other than by regulation of the rotor speed which, in some instances, may not be mechanically convenient.

The invention accordingly provides a flow machine of the type described in which the guide means includes means closing or substantially closing the ends of the machine and guide members extending the length of the rotor which are adjustable to vary flow conditions in the region of the interior of the rotor and thereby to regulate the throughput thereof with the rotor rotating in a given direction at a given speed. The guide means preferably include a pair of side walls positioned on opposite sides of the axis of the rotor having parts which are movable to provide the adjustable guide members.

It is often desired that the general direction of fluid flowing through a flow machine be reversed. With certain types of flow machines this can be done only by reversing the direction of rotor rotation. A cross-flow machine of the type described cannot be reversed in this manner and even in flow machines in which reversal of rotor direction causes a flow reversal, the control gear necessary to reverse the rotor rotation is relatively expensive. Further, flow machines in which flow reversal is achieved by rotor reversal are usually more efficient in one direction of flow than in the opposite direction.

An important object of the invention, therefore, is to provide a flow machine of the kind described which is capable of readily reversing the general direction of flow. Accordingly, the adjustable guide members are movable between a first and second position to reverse the general direction of flow through the machine.

Preferably, the side walls are so shaped that in operation of the machine with said movable wall parts in their first position a cylindrical fluid vortex of substantially the Rankine type is formed with the core of the vortex interpenetrating the blades at one angular location and with said movable wall parts in their second position forming a similar vortex at a diametrically opposed location.

Two embodiments of the invention are illustrated in the accompanying diagrammatic drawing in which:

FIGS. 1 and 2 are transverse sections of a reversible blower showing movable wall parts thereof in two different positions, and

FIG. 3 is a transverse section of a second form of blower.

Referring to FIGS. 1 and 2 of the drawing, the blower there shown comprises a rotor designated generally 1 having blades 2 extending between supporting end discs (not shown) which are mounted (by means also not shown) for rotation about the rotor axis in the direction indicated by the arrow 3. Inner and outer edges of the blades 2 lie on cylindrical envelopes shown at 4 and 5.

Patented Sept. 29, 1954 The blades 2 are concave facing in the direction of rotation and have their outer edges leading their inner edges.

A casing is provided about the rotor l which includes fixed side walls 7 and 3 extending the length of the rotor with uniform cross-section between fixed end walls one of which appears at 6. The side walls 7 and 25 with the end Walls define a pair of rectangular apertures 9 and 19 on opposite sides of the rotor which, as will be described hereinafter, form the inlet and outlet respectively of the machine with the position of the parts as shown in FIG. 1.

Middle portions 11 and 12 of the side walls 7 and 8 lie on a plane containing the rotor axis and are separated from the outer envelope 5 of the rotor blades 2 by substantially more than a working clearance. The wall 7 has a portion 13 converging with the rotor 1 in the direction of rotation thereof from a lip 14 adjacent the aperture 9. The wall 8 has a portion 15 leading from the aperture 9 to a point 16 near the rotor 1 but spaced radially therefrom and a further wall portion 17 between the middle portions 12 and 16, this latter wall portion 17 appearing in transverse section as an arc centered on the axis 18.

On the opposite side of the rotor, the side wall 7 provides wall portions 15' and 17 which are similar to the portions 15 and 17 of the wall 3 just described. The side wall 8 likewise provides a lip 14' and wall portion 13' similar to the lip 14 and wall portion 13 of the wall 7 mentioned above.

It will be seen that the parts of the walls 7 and 8 facing the apertures 9 and 16 form a reversed mirror image of one another on the plane containing the portions 11 and 12. Alternatively, the walls '7 and it can be regarded as mirror images of one another with respect to the rotor axis.

Movable auxiliary wall portions 2% and 2% made of thin sheet material are pivoted on pins located upon the axes 18 and 18' and extend therefrom up to the wall portions 17 and 17' respectively. Each of auxiliary wall portions Z9 and 26' can adopt either of two positionsin one it lies retracted against the wall portion 15 or 15 and in the other it provides a smooth transition from that part of the wall portion 15 or 15 which lies adjacent the aperture 9 or 16 to the wall portion 13' or 13, respectively. Each of auxiliary wall portions 29 and 29 carries an arm 21 or 21' extending from a point remote from the axes l8 and 18', the outer ends of these arms being formed as followers to cooperate with a cam 22 and being interconnected by a tension spring 23 to maintain contact between the arms and the cam. The cam 22 is rotatable through about the same axis as the rotor. Thus it will be seen that the auxiliary wall portions 20 and 28' move together as the cam 22 is moved, and will be positioned either as shown in PEG. 1 with the auxiliary wall portion 2t retracted and the auxiliary wall portion in fairing smoothly into the portion 13;, or vice versa as shown in FIG. 2 with the portion 2E" retracted and the portion 2% fairing into the wall portion 13. The arms 21 and 21, cam 22 and spring 23 are, of course, located where they will not obstruct flow.

With the auxiliary wall portions 20 and Ztl in the FIG. 1 position, the interaction of the rotor 1 and wall portion 13 converging therewith sets up a cylindrical fluid vortex which is substantially a Rankine type vortex when the rotor is rotated and a fluid is passed through the machine. The core of the vortex, which interpenetrates the blade envelopes, is indicated at V, and the resulting flow through the rotor is shown by the chain lines F. Formation of such a vortex increases the eificiency of a cross-flow fluid machine where the fluid passes first through the path of the rotating blades from the inlet of the machine into the interior of the rotor and secondly, through the path of the rotating blades from the interior of the rotor to the outlet. The formation of such vertexes and their effect on fan etficiency is described in copending application Serial No. 671,114, now abandoned.

With the auxiliary wall portions as and 20' in the FIG. 2 position, the interaction of the rotor l and wall portion 13 converging therewith sets up a vortex similar to that of FIG. 1 except that its core is in a diametrically opposite position. It is seen that the general direction of flow through the rotor is then in the opposite direction to that of FIG. 1.

It will be understood that the parts of wall portions 15 and 15' behind the respective movable auxiliary wall portions and 241' are ineffective to guide flow, and present simply for reasons of constructional convenience.

It will be appreciated that the blowers shown in H63. 1 and 2 have their wall portions 20 and 29' in extreme limits of movement or in two limit positions. As the cam 22 is turned from the FIG. 1 to the FIG. 2 position, with out changing the speed of the rotor, the throughput will diminish smoothly from its maximum value to zero (corresponding to a 90 movement of the cam) where the portions 20 and 29 will occupy a median position midway between the two limit positions shown in FIGS. 1 and 2 and the throughput will then build up again in the opposite direction to the maximum as the cam is turned beyond 90.

In the FIG. 3 blower, the rotor 1 is similar to that of FIGS. 1 and 2 and its parts are similarly designated. End closure walls 3%, only one of which is shown, are provided and side walls extend with uniform cross-section between the end walls. The side walls comprise similar plane fixed walls 31 and 32, extending away from the rotor 1 on either side thereof and movable walls 33 and 34 mounted by linkages 35 and 3% supported on extensions of the end walls 3% so as to move always parallel to themselves. Each of the linkages 3S and 36 includes a pair of bell-crank levers 40 and 41 pivoted at fixed points 42 and 43 respectively and having their long arms articulated at 4 5 and 45 to the respective movable walls 33 and 34 and their short arms interconnected by a link 46.

The movable walls 33 and 34 each include a plane part 37 or 37' remote from the rotor l and parallel to the fixed walls 31 and 32, and a curved part 38 or 33 adjacent the rotor and diverging therefrom in the direction of rotor rotation. The walls 33 and 34 can each adopt either an inward position wherein the curved part 38 or 38 lies close to the rotor 1 and meets the corresponding fixed wall 31 or 32 where it lies nearest the rotor, or a retracted position wherein the curved part 38 or 3% lies some distance from the rotor and meets a fixed auxiliary wall 39 or 39' which extends towards the corresponding fixed wall 31 or 32 and meets it where it lies nearest the rotor. The movable walls 33 and 34 are moved together so that, as shown, one is in retracted and the other in its inward position. With the walls 33 and 34 positioned as shown, flow takes place through the rotor 1 as indicated by the flow lines F with a Rankine vortex being formed at the position indicated. Movement-oi each of the walls 33 and 34 to its other position will cause the general direction of flow to be reversed, the vortex forming at a diametrically opposed position.

As in the construction of FIGS. 1 and 2, the throughput can be regulated, without change of rotor speed, to any desired value between a maximum value in one direction to the same value in the other direction, by appropriate settings of the walls 33 and 34 intermediate their extreme positions.

The FIG. 3 construction has the advantage that the region of entry to the rotor 1 defined by the fixed and movable walls is of greater cross-section than is the exit region.

Where the rotor is relatively long, it is not absolutely necessary that its ends be completely closed in order that a vortex be formed. In a long rotor having its ends open, the vortex formed may be spoiled adjacent the rotor ends by axial inflow of fiuid into the rotor; however, the vortex will continue to exist over a major portion of the length of the rotor to give the uneven velocity profile that is a characteristic of cross-flow machines constructed as disclosed above.

I claim:

1. A reversible cross-flow blower, comprising a hollow cylindrically shaped rotor of finite length having a plurality of blade on its outer periphery, end walls substantially enclosing the ends of said rotor, two similarly shaped side walls extending the length of the rotor positioned on diametrically opposite sides thereof and forming with said end walls a casing substantially surrounding said rotor having two fluid flow openings, portions of said side walls being movable towards and away from said rotor between first and second limit positions to reverse the direction of flow of fluid through said blower, and connecting means connecting said movable portions so that when one said portion is moved toward said rotor, the diametrically opposite portion is movable away from said rotor whereby the flow of fluid through said blower may be regulated.

2. A cross-flow blower according to claim 1 wherein each said side wall includes a fixed vortex forming portion and an adjacent movable portion and wherein a fluid vortex is formed with the core of said vortex interpenetrating the path of the rotating blades when an adjacent movable portion is moved away from said rotor from a median position midway between said limit positions to a limit position and when said rotor is rotated.

3. A cross-flow blower according to claim 2 wherein the other of said vortex forming portions forms a second vortex diametrically opposite said first vortex'when the other said adjacent movable portion is moved away from said rotor from a median position to a limit position.

4. A blower according to claim 2 wherein said movable portions are mounted for movement towards and away ,7

from fixed portions of said side walls and wherein one opening defined by the end walls and one fixed and one movable side wall portion will be of a larger cross-sectional area than will the diametrically opposite opening.

5. A reversible cross-flow blower comprising a bladed cylindrically shaped rotor of finite length, means for rotating said rotor, end walls substantially enclosing the ends of said rotor, diametrically opposed first and second side walls extending the length of said rotor and forming with said end walls a casing having inlet and outlet openings, firstand second vortex formers included in said side walls for forming a first and second fluid vortex with the core of each said vortex interpenetrating the path of the blades of said rotor, and first and second flow guide means included in said first and second side walls movable towards and away from said rotor between first and second limit positions; said first vortex former forming said first vortex when said first movable fiow guide means is moved away from the rotor and toward a limit position to cause fluid to flow through said machine in one direction and said second movable wall moves towards said rotor, and said second vortex former forming said second vortex diametrically opposite said first vortex when said second movable flow guide means is'moved away from the rotor towards a limit position and said first movable flow guide is moved towards said rotor from said limit position to destroy said first vortex and cause a reversal of flow through said machine.

References Cited in the file of this patent UNITED STATES PATENTS 1,889,588 Anderson Nov. 29, 1932 2,205,902 McMahan June 25, 1940 2,658,700 Howell Nov. 10, 1953 3,036,696 I-leine-Geldern Apr. 23, 1963 

1. A REVERSIBLE CROSS-FLOW BLOWER, COMPRISING A HOLLOW CYLINDRICALLY SHAPED ROTOR OF FINITE LENGTH HAVING A PLURALITY OF BLADES ON ITS OUTER PERIPHERY, END WALLS SUBSTANTIALLY ENCLOSING THE ENDS OF SAID ROTOR, TWO SIMILARLY SHAPED SIDE WALLS EXTENDING THE LENGTH OF THE ROTOR POSITIONED ON DIAMETRICALLY OPPOSITE SIDES THEREOF AND FORMING WITH SAID END WALLS A CASING SUBSTANTIALLY SURROUNDING SAID ROTOR HAVING TWO FLUID FLOW OPENINGS, PORTIONS OF SAID SIDE WALLS BEING MOVABLE TOWARDS AND AWAY FROM SAID ROTOR BETWEEN FIRST AND SECOND LIMIT POSITIONS TO REVERSE THE DIRECTION OF FLOW OF FLUID THROUGH SAID BLOWER, AND CONNECTING MEANS CONNECTING SAID MOVABLE PORTIONS SO THAT WHEN ONE SAID PORTION IS MOVED TOWARD SAID ROTOR, THE DIAMETRICALLY OPPOSITE PORTION IS MOVABLE AWAY FROM SAID ROTOR WHEREBY THE FLOW OF FLUID THROUGH SAID BLOWER MAY BE REGULATED. 